Firearm identification system and method for forensic purposes

ABSTRACT

A system and method are disclosed for identifying a firearm by markings on the inside of the firearm. The markings leave an impression on the bullet casing, allowing the firearm to be identified from the markings left in the bullet casing. The markings could be symbols, characters, or a combination thereof. Tools for marking the firearm are also disclosed.

[0001] The present invention relates to a system and method for identifying a firearm, and more particularly, a system and method for placing markings on the inside of a firearm's firing chamber that will cause those markings to be imprinted on a bullet casing used with the firearm. The markings are specific to each firearm, allowing identification of the firearm that fired the bullet from the markings left on the bullet casing.

[0002] Currently, firearms are identified by a unique serial number that is inscribed into the frame of a firearm. This current identification method of inscribing a serial number into the frame does not have a means of transferring the serial number information to the bullet or its casing. Any identification of a firearm to a bullet that was fired from the firearm relies, if at all possible, on random markings left on the casings and bullet fragments by imperfections left on the interior surfaces of the firearm made during the manufacturing process. However, this method is imprecise and successful only if the gun is located shortly after the bullet casing in question is found and the gun is tested. The imperfections on the inside of the firearms may change after time, preventing identification if too much time or too many shots are fired from the firearm in question. Additionally, the firearm manufacturers do not record the markings made on bullet casings or bullets before the firearms are sold, so the firearms must first be located and then tested in order to match a particular bullet casing or bullet with a firearm.

[0003] Accordingly, the present invention is directed to a system and method for marking a firearm that substantially obviates one or more of the problems and disadvantages in the prior art. Additional features and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the apparatus and process particularly pointed out in the written description and claims, as well as the appended drawings.

SUMMARY OF THE INVENTION

[0004] To achieve these and other advantages and in accordance with the purpose of the invention as embodied and broadly described herein, the invention is directed to a firearm including a frame, a trigger, a firearm firing chamber, a barrel, and a firearm indicia formed on a predetermined internal portion of a surface of the firearm, wherein the firearm indicia comprises a predetermined pattern associated with data about the firearm.

[0005] In yet another aspect, the invention is directed to a method of identifying a firearm used to discharge at least one bullet casing, the firearm having firearm indicia formed on an internal surface of the firearm including the steps of reading a firearm indicia formed on a predetermined portion of the at least one bullet casing during the firing of the firearm, wherein the firearm indicia is associated with information about the firearm, and associating the firearm indicia on the at least one bullet casing with information corresponding to the firearm to allow for identification of the firearm.

[0006] In another aspect, the invention is directed to a firearm marking tool including a guide having a first end and a second end and a passage extending therebetween, the guide configured to fit within a firing chamber of the firearm and having a longitudinal axis, a drive element disposed within the passage at the first end of the guide and movable within the guide along the longitudinal axis, and scribing elements slidingly disposed within the guide between the first and second ends, the scribing elements sliding orthogonal to the longitudinal axis of the guide in response to the presence of the drive element.

[0007] In another aspect, the invention provides a method of marking a firearm with firearm indicia to allow identification of the firearm from a bullet casing used in the firearm including the steps of providing a firearm marking tool to mark the firearm, the tool capable of marking an interior portion of the firearm and using the tool to mark on the predetermined portion of the firearm the firearm indicia. A firearm barrel and firing chamber assembly comprising:

[0008] In yet another aspect, the invention is directed to firearm barrel and firing chamber assembly comprising a firearm firing chamber, a firearm barrel, and a firearm indicia formed on a predetermined internal portion of a surface of the firearm firing chamber, wherein the firearm indicia comprises a predetermined pattern associated with data about the assembly.

[0009] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

[0010] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification. The drawings illustrate several embodiments of the invention and together with the description serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a side view with a partial cutaway of a firearm in which embodiments of the firearm marking indicia according to the present invention could be used;

[0012]FIG. 2 is a partial cross sectional view of a firing chamber and barrel of firearm with firearm indicia according to one embodiment of the present invention;

[0013]FIG. 3 is an unfired bullet for use with the firearm of FIG. 2;

[0014]FIG. 4 is a fired bullet casing after ejection from the firearm of FIG. 2 with firearm indicia that has been transferred onto the external perimeter surface of the bullet casing;

[0015]FIG. 5 is a partial cross sectional view of a firing chamber and barrel of firearm with firearm indicia according to a second embodiment of the present invention;

[0016]FIG. 6 is a fired bullet casing after ejection from the firearm of FIG. 5 with firearm indicia that has been transferred onto the surface of the bullet casing;

[0017]FIG. 7 is a partial cross sectional view of a firing chamber and barrel of firearm with firearm indicia according to a third embodiment of the present invention;

[0018]FIG. 8 is a cross sectional view along the line 8-8 through the predetermined portion;

[0019]FIG. 9 is a fired bullet casing after ejection from the firearm of FIG. 7 with firearm indicia that has been transferred onto the surface of the bullet casing;

[0020]FIG. 10 is a perspective view of a firearm marking tool used to mark firearm indicia on a firearm according to one embodiment of the present invention;

[0021]FIG. 11 is a cross section view of the firearm marking tool in FIG. 10 along line 11-11;

[0022]FIG. 12 is a cross section view of the firearm marking tool in FIG. 10 along line 12-12;

[0023]FIG. 13 is an enlarged view of a scribing element of the firearm marking tool in FIG. 10;

[0024]FIG. 14 is a cross section view of the firearm marking tool of FIG. 10 disposed in a portion of a firearm;

[0025]FIG. 15 is a cross section view of a firearm marking tool used to mark firearm indicia on a firearm according to another embodiment of the present invention;

[0026]FIG. 16 is a cross section view of the firearm marking tool along lines 16-16 in FIG. 15;

[0027]FIG. 17 is cross section view of the firearm marking tool of FIG. 15 disposed in a portion of a firearm according to another embodiment of the present invention;

[0028]FIG. 18 is a cross section view of a firearm marking tool used to mark firearm indicia on a firearm according to another embodiment of the present invention;

[0029]FIG. 19 is a cross section view of a firearm marking tool used to mark firearm indicia on a firearm disposed in a portion of a firearm according to another embodiment of the present invention;

[0030]FIG. 20 is a cross section view of a firearm marking tool used to mark firearm indicia on a firearm according to another embodiment of the present invention;

[0031]FIG. 21 is an end view of the firearm marking tool of FIG. 20;

[0032]FIG. 22 is a cross section view of the firearm marking tool of FIG. 20 disposed in a portion of a firearm;

[0033]FIG. 23 is a cross section view of a firearm marking tool using a electric discharge machining (EDM) process to apply the firearm indicia to the firearm; and

[0034]FIG. 24 is a cross section view of a firearm marking tool using a laser to engrave the firearm indicia on the firearm.

DETAILED DESCRIPTION OF THE INVENTION

[0035]FIG. 1 illustrates one type of firearm 10 in which the present invention can be used. As with the illustrated firearm, most of the firearms include a frame 11, a trigger 13 to initiate the firing of the firearm 10, a barrel 14, and a firing chamber 12. In most of the firearms, barrel 14 and firing chamber 12 are of unitary construction. However, the present invention is not limited to the type of weapon or the construction of the barrel and firing chamber. The firing chamber and the barrel may be separate pieces but are consider to be an assembly in the present invention. A portion of a barrel 14 and firing chamber 16 is illustrated in FIG. 2 illustrating one embodiment of the present invention. While one configuration of a firearm is illustrated in the figures, the present invention is not so limited. The present invention also applies to any firearm that uses any type of ammunition with a form of casing, which may consist of a shell and projectile(s), such as bullets, and shells and pellets. Interior surface 16 of firing chamber 12 has firearm indicia 18 formed therein. In the embodiment illustrated in FIGS. 2-4, the firearm indicia 18 includes a series of lines 20, wherein some of lines 20 may be thicker and some may be thinner than other of the lines 20. The combination of lines 20 and spaces therebetween of the firearm indicia 18 represent information about the firearm 10 as described in more detail below.

[0036] As is known in the art, the firing chamber 12 is circular in cross section and therefore has a circumference. In the preferred embodiment, the firearm indicia 18 extends around at least a portion of the circumference of the firing chamber 12, as illustrated in FIG. 2. The firearm indicia 18 could be oriented 180° from that shown and extend along the firing chamber 12 in a front-to-rear or rear-to-front direction. However, the firearm indicia 18 is preferably mounted as far forward in the firing chamber 12 as possible and as close to shoulder 22 and barrel 14 as possible. The shoulder 22 acts as a stop to keep the bullet 25 (see FIG. 3) in firing chamber 12. Close contact of the bullet 25 and the firing chamber 12 keeps the gun powder, gases, and other by-products of the firing of the firearm from coming around the bullet casing 26 and towards the operator. If the firearm indicia 18 is mounted as forward as possible in the firing chamber 12, there is less likelihood that the firearm indicia 18 could be removed as it would be difficult to access. Additionally, the closer the firearm indicia 18 is to the shoulder, attempts to remove the firearm indicia 18 would more likely result in damage to the shoulder 22, allowing for “blow-back” and a reduced effectiveness of the firing of the firearm. In fact, it could even damage the firing chamber 12 and barrel 14 such that the firearm or firing chamber/barrel assembly is no longer useful. Preferably the firearm indicia 18 is located about 5 mm from the shoulder 22 and more preferably is located about 1 mm from the shoulder 22.

[0037] When the firearm 10 is fired and the bullet 24 leaves through the barrel 14, the firearm indicia 18 is transferred to the bullet casing 26. The force of the explosion resulting from the firing causes the bullet casing 26 to expand and press against the interior surface 16 of firing chamber 12. When the bullet casing 26 is malleable, the firearm indicia 18 are transferred to the bullet casing 26 from the force of the explosion during firing to form a mirror image 18′ of the firearm indicia 18.

[0038] The firearm indicia 18 are preferably lines scribed into the interior surface 16 of the firing chamber 12 as illustrated in FIG. 2. The pattern of the lines could be a bar code or other code to identify the firearm by the information contained in the firearm indicia 18. As illustrated in FIGS. 5 and 6, the firearm indicia 28 could also be a series of alphanumerical characters. In FIG. 5, the alphanumeric characters inscribed in the firearm indicia 28 also allow for identification of the particular firearm. As with the firearm indicia 18 in FIG. 2, the firearm indicia 28 in FIG. 5 is also transferred to the bullet casing 26. It should be noted that while the alphanumeric characters in FIGS. 5 & 6 and the lines in FIGS. 2 & 4 appear inverted in firing chamber and forward on the bullet casing, it could be reversed so that the characters appear inverted in the bullet casing and not in the firing chamber.

[0039]FIGS. 7-9 illustrate that the firearm indicia 30 may also be raised relative to a portion 32 where it is placed. As illustrated in FIG. 8, the firearm indicia 30 is raised relative to the surface of the portion 32 of firing chamber 12 and is generally even with the interior surface 16 of the firing chamber 12. The indicia 30 and recessed portion 32 are both impressed onto the bullet casing 26 to form a mirror-image indicia 30′ and a raised portion 32′. See FIG. 9.

[0040] The firearm indicia 18,28,30 corresponds to data that can uniquely identify the firearm or, in the alternative, the portion of the firearm that includes the firing chamber 12 and barrel 14. The firearm 10 can be any type of firearm, including a hand gun, a rifle, and a shotgun. The firearm indicia 18,28,30 would preferably include unique and identifying numbers, characters, lines, dots, alphanumeric characters or other symbols that can be associated with the firearm and the firing chamber/barrel assembly. These symbols would be able to identify data that would include the serial number of the firearm, a registration number, the firearm manufacturer, the date of manufacture, the firearm model number, special edition, and the caliber of the firearm and identify the particular firearm or firing chamber/barrel assembly used. It is anticipated that a unique registration number separate and apart from the serial number on the frame could be used. If the registration number is different from the serial number on the frame, it could be linked in a database to the serial number or other identifying information. Also, if the firing chamber/barrel is a replacement part, it may also have a separate registration number that could be associated with a specific serial number or person purchasing the replacement.

[0041]FIGS. 9 & 10 illustrate one embodiment of a firearm marking tool 40 that can be used to scribe the firearm indicia 18,28,30 into the firearm 10. The firearm marking tool 40 includes a guide 42 having a first end 44, a second end 46, a passage 47 therebetween, and a drive element 48. The firearm marking tool 40 may also have an extension 50 that assists in locating the tool 40 in a firearm 10. See, e.g., FIG. 14. Drive element 48 includes a shaft 52 with a conical section 54 at the first end 56 and a drive head 58 at the second end 60. The first end 56 of the drive element 48 is inserted into the first end 44 of the guide 42 and slidingly moves along and within the passage 47. A resilient element 62 is disposed around drive element 48 and between the first end 44 of the guide 42 and the drive head 58. The drive head 58 and the first end 44 are configured to allow the resilient member 62 to engage each other to bias the drive element 48 away from the guide (or to the left in the figures). While a spring is illustrated in the figures, any resilient member could be used. For example, elastomeric material in the shape of a sleeve around drive element 48 can be used.

[0042] The firearm marking tool 40 also has scribing elements 64 to mark the firearm indicia 18,28,30 on the interior surface 16 of the firing chamber 12. The scribing elements 64 are located in individual channels 66 in the guide 42. As shown in FIG. 12, there are eight scribing elements 64 and channels 66. However, any number of scribing elements 64 and channels 66 could be used with the guide 42. Additionally, while the scribing elements 64 are located evenly around the circumference of the guide 42, they could have different spacing or be left empty (no scribing elements 64 inserted into the channels 66) to scribe the correct pattern on the firearm 10.

[0043] The scribing elements 64 preferably have a shaft 68, a drive element engagement surface 70 and a firearm engagement surface 72. When the drive element 48 is moved in the direction of the arrow F1 in FIG. 11, the conical section 54 is moved forward to engage the drive element engagement surfaces 70 of shafts 68. See FIG. 13. The scribing elements 64 move radially outward (in the direction of arrows F2) to engage the firing chamber surface 16 and form the firearm indicia 18. When the drive element 48 is returned to the biased position to the left, the scribing elements 64 are no longer forced into the firing chamber 12 and no further marks are made. Each of the firearm engagement surfaces 72 would typically have at least one alphanumeric character to imprint into the firing chamber 12. See, e.g., FIG. 5. The firearm engagement surfaces 72 may also have dots, dashes or other symbols that are used to make the indicia 18,28,30.

[0044] An alternative embodiment of the firearm marking tool is illustrated in FIGS. 15-17, which is similar to the prior embodiment except that the firearm marking tool 40′ has a retainer element 74 that is attached to each of the scribing elements 64′ to provide an inward force to pull each of the scribing elements 64′ toward the passage 47 in the tool 40′. While a single spring ring 74 is illustrated in the figures, one retainer member 74 for each of the scribing elements 64′ could also be used. The scribing elements 64′ each have a groove 76 to engage the retainer element 74.

[0045] Another embodiment of the firearm marking tool 80 is illustrated in FIG. 18. The tool 80 is similar to the other two embodiments above, but the guide 82 has a reduced area 84 that is configured to engage the conical section 54 of the drive element 52. This configuration at the second end 86 of the guide 82 prevents the drive element 52 from advancing too far and pushing the scribing elements 64 too far out and into the wall of the firing chamber. While the retainer element 74 is not shown in FIG. 17, it could be used with the scribing elements 64 as well, provided the grooves are also present.

[0046] Another embodiment of the firearm marking tool 90 is illustrated in FIG. 19. The drive element of the previous embodiments has been replaced in the tool 90 with a drive element 92 that is connected to a reciprocating member of a pneumatic controller or a hydraulic controller. The first end 94 of the drive element 92 in this embodiment also has a conical shape as in the other embodiments. The drive element 92 is connected to the controller through a coupling 96. The coupling 96 is attached to the drive element 92 by a coupling pin 98 inserted into a coupling bore 100 and engages a hole 102 in the drive element 92. The coupling 98 moves in the directions of the arrows A to cause the scribing elements 64 to move as in the previous embodiments.

[0047] The first end 104 of the guide 106 is different from that of the previous embodiments. The first end 104 of the guide 106 is more elongated than the previous embodiments to allow the scribing elements 64 to be moved forward in the guide 106 to allow for marking of the firing chamber 12 closer to the shoulder 22.

[0048] Another embodiment of the firearm marking tool is illustrated in FIG. 20. The firearm marking tool 110 is connected by a coupling 112 to a hydraulic or pneumatic controller as in the previous embodiment. The coupling 112 is attached to the drive element 114 by a coupling pin 116 inserted into a coupling bore 118 and engages a hole 120 in the drive element 114. However, rather than the drive element of the previous embodiments, drive element 114 of this embodiment is larger in diameter and replaces the drive element and guide of those embodiments. The drive element 114 is slightly smaller in diameter than the firing chamber 12. At the end of the drive element 114 is an attachment assembly 122 with a screw 124 that allows for interchangeable scribing segments 126. The screw 124 threadingly engages the first end 128 of the drive element 114, although other attachment methods are also possible, such as quarter turns, a cross pin similar to the couple pin 116, bayonet slots, press fit, and adhesives. The scribing segments 126 either have a scribing element 130 or a flat element 132. The scribing elements 130 can have a number of widths to scribe a variety of lines in the firing chamber 12. The arrangement of the scribing elements 130 and flat elements 132 can be used and changed as needed to compose the firearm indicia for each firearm. The firearm marking tool 110 can also be moved along the length of the firing chamber to create the lines 20 as illustrated in FIG. 2.

[0049]FIG. 23 illustrates the use of a wire or electrode 140 used with an electric discharge machining (EDM) process. A precision wire EDM machine removes metals from metal blocks, such as the firing chamber of a firearm, by creating thousands of electrical discharges per second that flow between a wire and the metal blocks, vaporizing metal in the controlled area. The motion of the wire may be controlled by any commercially available computer numerical control (CNC) software. The firearm indicia 18 can be programmed into the computer (not shown) and the EDM will create the firearm indicia 18. It should be noted that although the line form of the indicia is illustrated in FIG. 23, the character form or any other form could also be formed using the EDM process.

[0050]FIG. 24 illustrates the use of a laser beam 150 from a laser beam generator 152, where the laser beam light energy is used to remove material from the firing chamber wall 12 in a pattern that result in firearm indicia 18. The laser beam generator is a machine that can be precisely controlled by a CNC machine and software.

[0051] It will be apparent to those skilled in the art that various modifications and variations can be made in the firearm marking indicia and tools of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

We claim:
 1. A firearm comprising: a frame; a trigger; a firearm firing chamber; a barrel; and a firearm indicia formed on a predetermined internal portion of a surface of the firearm, wherein the firearm indicia comprises a predetermined pattern associated with data about the firearm.
 2. The firearm of claim 1, wherein the data includes at least one of a serial number, a registration number, firearm manufacturer, the date of manufacture, the firearm model number, special edition, and the caliber.
 3. The firearm of claim 1, wherein the firearm indicia comprises at least one alphanumeric character.
 4. The firearm of claim 1, wherein the firearm indicia comprises at least one symbol.
 5. The firearm of claim 1, wherein the predetermined portion is recessed relative to the internal surface and the firearm indicia is raised relative to the recessed predetermined portion of the internal surface and generally even with the internal surface.
 6. A method of identifying a firearm used to discharge at least one bullet casing, the firearm having firearm indicia formed on an internal surface of the firearm, comprising the steps of: reading a firearm indicia formed on a predetermined portion of the at least one bullet casing during the firing of the firearm, wherein the firearm indicia is associated with information about the firearm; and associating the firearm indicia on the at least one bullet casing with information corresponding to the firearm to allow for identification of the firearm.
 7. A firearm marking tool comprising: a guide having a first end and a second end and a passage extending therebetween, the guide configured to fit within a firing chamber of the firearm and having a longitudinal axis; a drive element disposed within the passage at the first end of the guide and movable within the guide along the longitudinal axis; and scribing elements slidingly disposed within the guide between the first and second ends, the scribing elements sliding orthogonal to the longitudinal axis of the guide in response to the presence of the drive element.
 8. The firearm marking tool of claim 7, further comprising: a pneumatic controller attached to and in communication with the drive element to move the drive element relative to the guide.
 9. A method of marking a firearm with firearm indicia to allow identification of the firearm from a bullet casing used in the firearm, comprising the steps of: providing a firearm marking tool to mark the firearm, the tool capable of marking an interior portion of the firearm; and using the tool to mark on the predetermined portion of the firearm the firearm indicia.
 10. The method of marking a firearm of claim 9, further comprising the step of establishing a predetermined pattern as the firearm indicia, wherein the firearm indicia is associated with data about the firearm.
 11. The method of marking a firearm of claim 9, wherein the marking tool is at least one electrode from an electric discharge machine.
 12. The method of marking a firearm of claim 9, wherein the marking tool is a laser.
 13. The method of marking a firearm of claim 9, wherein the marking tool is a sharp element capable of inscribing metal.
 14. The method of marking a firearm of claim 9, wherein the marking tool is controlled by a computer processing unit.
 15. A firearm barrel and firing chamber assembly comprising: a firearm firing chamber; a firearm barrel; and a firearm indicia formed on a predetermined internal portion of a surface of the firearm firing chamber, wherein the firearm indicia comprises a predetermined pattern associated with data about the assembly.
 16. The assembly of claim 15, wherein the data includes at least one of a serial number, a registration number, firearm manufacturer, the date of manufacture, the firearm model number, special edition, and the caliber.
 17. The assembly of claim 15, wherein the firearm indicia comprises at least one alphanumeric character.
 18. The assembly of claim 15, wherein the firearm indicia comprises at least one symbol.
 19. The assembly of claim 15, wherein the firearm indicia is inscribed into the predetermined portion of a surface of the firing chamber.
 20. The assembly of claim 15, wherein the predetermined portion is recessed relative to the internal surface and the firearm indicia is raised relative to the recessed predetermined portion of the internal surface and generally even with the internal surface. 